Results: Stage 2, B58 (X3 M40i)
I've had the car for a few months now.
Lowered it right away. Did stage 1 tune (91 tune). Felt good. Did a catted downpipe and stage 2 yesterday (93 octane tune). Big gains. Feels violent at 2,000rpm when the turbo is spooled.
Sound is good. Quiet on startup, decel pops are pretty quiet. Good aggressive upshift sound at WOT in sport mode.
Stock rated
hp: 360
tq: 370
Stage 2 (tune + downpipe)
hp: 455
tq: 490
The tune: https://www.protuningfreaks.com/prod...0i-m140i-m340i
According to the link above, adding a high pressure fuel pump will apparently add another 60hp/130tq. I may do that in the spring. Honestly tho, it's plenty fast for now haha.
Ran 12.44 at 110mph today on dragy with a full tank, 2 car seats, winter tires.
Still room for improvement in the 60ft time, as I didn't mange to figure out launch control. Just brake boosting.
For $50kish used, I really can't think of a more fun bang for the buck family hauler.
Current Cars:
2019 BMW X3 M40i Stage 2, 12.44 at 110mph
1972 Chevy Super Cheyenne C10 Pickup 402 big block, 700R4
2004 GMC 2500HD 8.1L
Past Cars:
1970 Chevy Blazer, 2wd
2003 BMW X5 4.6IS Doushmobile, moneypit
2015 Ford Fiesta ST | Cobb Stage 1, catless downpipe
2008 Corvette Z06 - 11.39 at 123.8mph
2002 Corvette Z06 - 12.10 at 116.5mph
2005 Jeep Wrangler LJ
1993 5L Mustang - 12.59 at 108mph
1989 5L Mustang
1990 Jeep Cherokee
1991 Acura Integra RS 403Honda